Electric plug



UCL 9, 1934. w M. Els v 1,976,024

ELECTRI C PLUG Filed April 21, 1932 2 Sheets-Sheet l A TTORNEY Oct. 9, 1934. w KNEYIS 1,976,024

ELEGTRI C PLUG Filed April 21, 1932 2 Sheets-Sheet 2 ATTORNEY Patented Get. 9, 1934 STATES ELECTRIC PLUG Application April 21, 1932, Serial No. 606,622 13 Claims. (01. 173 -332) mas,

The present invention relates to improvements in electric plugs of various designs.

It has been found where small threaded bolts with nuts, together with screws or the like, are used to hold together the two halves of the well known electric plug of the type used particularly for connecting an electric iron to the house current, that these small threaded bolts with their nuts are constantly becoming loose and at times completely falling out. This permits the two halves of the electric plug, which forms the housing or casing for the electric terminals therein, to become inoperative, and at times causing short circuiting of the electric current in the home, with the resultant possibilities of shock to the housewife and serious fire damage.

In the manufacture of these plugs these screws, or threaded bolts and their nuts, represent/an enormous amount of tedious effort and labor in the line 55 of Figure 1, disclosing the spring applying them to the electric plugs. They are also a continual bother to the average housewife, if she is of a practical turn of mind, to keep the same tight.

It is the purpose of the present inventor to provide a snaptight, unbreakable, metal enclosed electric plug adaptable for use on all electric appliances, such as electric irons, electric toasters, electric coffee percolators and electric appliances of similar construction, requiring aconnection from the source of electricity to the electric appliance.

The invention consists broadly of a casing, which may or may not have a metal exterior casing, either for a portion or the whole structure, the said casing being divided into halves, which halves are fastened to each other by a spring snap, allowing for a constant and positive engagement of the two halves of the plug at all times, without the use of screws or threaded bolts and nuts.

An important object of the present invention is to provide means whereby the two halves of the electric plug as hereinbefore described are held together in a positive manner without possibility of disalignment of the two halves due to loosening of the holding means.

Still another object of the present invention is to provide means whereby an electric plug of the type described may be held together without use of screws, threaded bolts and the like in a positive manner.

Another important object of the present invention is toprovide spring-snap means, adaptable to various designs, materials and combinations thereof, for holding in positive and proper entrated several forms of electric plugs embodying the various features of my invention in their preferred forms.

Figure 1 is a front elevation of my electric plug having a complete metallic casing.

Figure 2 is a side elevation of the same.

Figure 3 is a view similar to Figure l, disclosing the inner structure of the plug after the upper half of the same has been removed.

Figure 4 is an end view of Figure 1.

Figure 5 is an enlarged sectional view taken on snap structure.

Figure 6 is a plan View of the electric plug as shown in Figure 1.

Figure '7 is a front elevation, similar to Figure 1, disclosing an electric plug, having my invention applied thereto, the two halves of which are made entirely of bakelite or similar material.

Figure 8 is an end elevation of Figure 7.

Figure 9 is a fragmentary sectional view of a slightly modified form of plug that may be taken on line 99 of Figure '7, merely for purposes of locating the section on a plug of similar structure.

Figure 10 is still another form of electric plug having my invention applied thereto.

Figure 11 is a fragmentary sectional view of the same taken on the line 11-11 of Figure 10.

Figure 12 is an inverted plan view in perspective of one of the metallic interlocking springsnap members as shown in Figure 10.

Referring to the drawings by numerals each of which represents the same or similar parts throughout the various views, the invention consists of an electric plug 1 composed of an upper or male half 2 and a lower or female half 3, each of said halves having metal coverings or casings s and 5 respectively. 7 These casings in the present instance being integral with the inner bakelite structure of their respective halves, which may be identified by numerals 6 and '7 respectively.

The casings 4 and 5 have each formed on their seen, for purposes of engaging the upper half 2 to the lower half 3, it is only necessary to see that both halves register properly one with the other, as shown partially in fine dotted lines in Figure 5 of the drawings, and then by pressing the two halves together the lower beading 9 will be caused to move or spring outwardly in the direction of the arrow indicated at 10, until the upper beading, 8 has passed the high point 11 of the beading 9, whence it will be sprung or snapped into the recessed portion 12 of the lower beading as shown. This creates a positive and permanent engagement between the two halves 2 and 3 composing the body of the electric plug member 1.

The curved or extended portions 14 and 15 of the two halves of the plug structure prevent any longitudinal movement between these two members.

The inner portions of the two halves 2 and 3 may be fully covered and filled in with Bakelite, or similar non-conduoting material 16, which in turn may be properly recessed to receive the usual electrical contact terminals 18, the electric wiring and cord and spring structure indicated at 19. For purposes of readily opening or separating the two halves with a tool I have provided the offset portions and 21 which form the tool purchase openings 22.

Referring to Figures '7 and 8 of the drawings, I have disclosed an electric plug 20 made up wholly of Bakelite, 21 or material having similar characteristics, the structure of which is similar to that shown in Figures 1 to 6, applying the same reference numerals thereto for similar parts and structure as shown in the figures referred to.

In Figure 9 of the drawings is shown a slightly different form of interlocking-spring snap beading 25. The plug 26 to which it is applied is similar in structure to that shown in Figures 7 and 8. This particular design presents a somewhat better appearance. The upper half 27 projects over the beading 29 at 28 as shown. The interlocking spring snap beading 29 and 30 of the lower and upper halves respectively being similar in structure and operation to that shown in Figures 1 to 6 of the drawings.

Referring to Figures 10, 11 and 12 of the drawings, I have disclosed another form of electric plug having the principle of my invention applied thereto.

In this instance the plug structure is composed of two Bakelite, halves 36 and 37 having an interlocking spring snap metallic casing 38 positioned thereon for holding said halves together. For purposes of anchoring the casing 38 composed of upper and lower members 39 and 40, one to the other and also to the plug member 35, I have provided the same with my interlocking spring snap connection indicated at 41, which in turn, has in combination therewith the extended tab members 42. These tabs 42 are positioned in the slotted portion 43 and prevent longitudinal play between the members 39 and 40. For purposes of positioning said members to the plug proper I have provided extensions 45 to fit into the depressions 46 of the plug structure.

Thus a complete and easily assembled plug binding member is provided at very little cost, where it is desirous to have the combination of a metallic protective casing or binding means, with a Bakelite, electric plug.

I have thus described my invention in detail in order that its operation and structure may be fully understood; however, the terms herein are used in their descriptive sense only and not in a limited manner. The scope of the invention is defined in the claims:

What I claim and desire to secure by Letters Patent is:

1. An electric plug, composed of a plurality of separate interlocking units, and outer longitudinal and angular co-acting edges, said units having integral yielding, interengaging and locking means formed at the outer longitudinal and angular co-acting edges thereof, said yielding, integral, interengaging and locking means holding the said units together in locked position, and against relative movement.

2. An electric plug casing, composed of separate longitudinally divided units, having outer longitudinal and angular edges, the outer longitudinal and angular edges of said units having yielding, interengaging and locking means formed integral therewith for the purpose of holding said units together and against relative movement.

3. An electric plug composed of separate units, having co-acting, yielding means for holding said units together in locked relation against relative movement, one with the other, in the form of yielding inter-locking edges, formed integral with said units and positioned in juxtaposition to portions of longitudinal and angular outer edges formed on said units, said yielding inter-locking edges consisting of an inter-locking bead and yielding flange and groove structure co-active therewith.

4. An electric plug composed of upper and lower halves having co-acting bead and yielding flange and groove structures running along portions of longitudinal and angular outer engaging meeting edges formed integral therewith for purposes of inter-looking said members together against relative movement.

5. An electric plug having a casing composed of insulating material and consisting of separate units comprising upper and lower half members having longitudinal and curved meeting edges, said units having co-acting, inter-engaging and yielding locking means formed integral at portions of the longitudinal and curved meeting edges of said units, and substantially coinciding with said meeting edges for holding said units together in fixed and locked relation one to the other against relative movement.

6. An electric plug having an inner structure of insulating material, and an outer metallic casing structure in combination therewith, said plug and its metallic casing divided into separate units, the said casing units being provided at certain portions with meeting edges having coacting, expanding and contracting inter-locking means running in a continuous manner along said meeting edges for maintaining said units in locked and fixed relation one with the other, and against relative movement.

7. An electric plug, longitudinally divided forming upper and lower separate members, an auxiliary outer metallic casing therefor, also longitudinally divided into upper and lower members, said metallic casing members having co-acting, interlocking, yielding means formed integral with the said casing members along portions of oppositely disposed longitudinal and angular outer edges formed thereon in a substantially continuous manner for purposes of holding said upper and lower separate members constituting the electric plug proper in positive and locked engagement one with the other, and against relative movement S. An electric plug having upper and lower members, an auxiliary outer casing therefor composed of two separate members said members having co-acting interlocking means formed at their opposite edges on each side thereof for purposes of holding said upper and lower memers in positive engagement one with the other, upper and lower members together with said auxiliary outer casing members having interengaging means one with the other for purposes of preventing longitudinal movement between said upper plug member and said lower plug member with said auxiliary outer casing members.

9. An electric plug having upper and lower members and auxiliary outer casing members said members having co-acting interlocking means formed at their opposite edges on each side thereof for purposes of holding said upper and lower members in positive engagement one with the other, co-operative means on said plug and auxiliary members for preventing longitudinal movement between both the upper and lower plug members together with their auxiliary outer casing members.

is. An electric plug casing divided on a plane substantially parallel to its longitudinal axis, forming upper and lower half members, said members having at certain portions of outer longitudinal and curved meeting edges formed thereon and integral therewith, co-acting, interengaging, and inter-locking bead and yielding flange and groove structures, running substantially in a continuous manner along portions of the said longitudinal and curved edges for holding said upper and lower half members together in positive locked engagement with each other and against relative movement.

11. An electric plug composed of upper and lower halves, having co-acting, fixed and yielding means for holding said halves together against relative movement, and in a locked and positive manner, said means being in the form of a springsnap interlocking structure consisting of substantially continuous beading, which inter-engages and inter-locks with substantially continuous yielding and contracting, over-lapping groove structures, said beading and groove structures both running in a substantially continuous manner one with the other, along portions of longitudinal and outer angular meeting edges formed on the said upper and lower half members.

12. An electrical utensil plug comprising upper and lower separated halves of insulating material having longitudinal and angular meeting edges, said halves having integral resilient, inter-locking means on said longitudinal and angular outer meeting edges, whereby the halves may be snapped together and held against relative movement.

13. An electric plug composed of two separate members, one of said members having longitudinally formed beads along its longitudinal edges, the other member having yielding flanges and grooves, also longitudinally formed, along the longitudinal edges of said other member, said flanges and grooves yielding in a manner whereby the said members having bead and yielding flange structures may be snapped together to cause the groove and bead structures to interlock for purposes of securing the parts together.

WILLIAM M. KNEIS. 

